Table 1. International Collaboration by US Scientists.

Period	IC	hESC Total	hESC Derivation	hESC Differentiation	hESC Application	RNAi
1998–2008	IC (A)	175	26	101	39	267
	US only (B)	248	11	170	62	913
	Total (C)	423	37	271	101	1180
	% of IC (A/C*100).	41.37	70.27	37.27	38.61	22.63
1998–2001	IC(A)	10	2	4	1	58
	US only (B)	4	0	3	4	221
	Total (C)	14	2	7	5	279
	% of IC (A/C*100).	71.43	100.00	57.14	100.00	20.79
2002–2005	IC (A)	43	4	35	13	129
	US only (B)	65	1	51	23	407
	Total (C)	108	5	86	36	536
	% of IC (A/C*100).	39.81	80.00	40.70	36.11	24.07
2006–2008	IC (A)	122	20	62	25	80
	US only (B)	179	10	116	39	285
	Total (C)	301	30	178	64	365
	% of IC (A/C*100).	40.53	66.67	34.83	39.06	21.92

IC: international collaboration.